US6528820B1ExpiredUtility

Semiconductor device and method of fabricating same

Assignee: SEMICONDUCTOR ENERGY LABPriority: Jan 19, 1996Filed: Jan 17, 1997Granted: Mar 4, 2003

Est. expiryJan 19, 2016(expired)· nominal 20-yr term from priority

Inventors:Shunpei Yamazaki Satoshi Teramoto Jun Koyama Yasushi Ogata Masahiko Hayakawa Mitsuaki Osame Hisashi Ohtani Toshiji Hamatani

H10P 36/07H10P 36/03H10P 14/3816H10P 14/3806H10P 14/3456H10P 14/3411H10P 14/2921H10D 64/01332H10D 30/0321H10D 30/6739H10D 62/40H10D 86/0251H10D 86/0225H10D 86/425H10D 86/201H10D 30/6731H10D 30/6715H10D 30/0316H10D 30/0314H10D 86/60H10D 30/6745H10P 95/402

PatentIndex Score

114

Cited by

215

References

Claims

Abstract

There is disclosed a method of fabricating a thin-film transistor having excellent characteristics. Nickel element is held in contact with selected regions of an amorphous silicon film. Then, thermal processing is performed to crystallize the amorphous film. Subsequently, thermal processing is carried out in an oxidizing ambient containing a halogen element to form a thermal oxide film. At this time, the crystallinity is improved. Also, gettering of the nickel element proceeds. This crystalline silicon film consists of crystals grown radially from a number of points. Consequently, the thin-film transistor having excellent characteristics can be obtained.

Claims

exact text as granted — not AI-modified

What is claimed is:

1. An electroluminescence display device having a display portion, comprising:
a substrate having an insulating surface; and
a plurality of thin film transistors in said display portion over said substrate, each thin film transistor having an active layer formed by patterning a semiconductor film which has a thickness of 100 to 700 Å,
wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film, and
wherein crystal growth directions in said active layers differs from one of said plurality of thin film transistors to another, respectively.

2. A device according to claim 1 wherein said semiconductor film comprises silicon.

3. A device according to claim 1 wherein said electroluminescence display device is an active matrix type display device.

4. A device according to claim 1 wherein said electroluminescence display device is included in an electro-optical device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

5. An electroluminescence display device having a display portion comprising:
a substrate having an insulating surface; and
a plurality of thin film transistors in said display portion over said substrate, each thin film transistor having an active layer formed by patterning a semiconductor film which has a thickness of 100 to 700 Å,
wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film, and
wherein directions of anisotropy of crystal structures in active layers differs from one of said plurality of thin film transistors to another, respectively.

6. A device according to claim 5 wherein said semiconductor device is an active matrix type display device.

7. A device according to claim 5 wherein said electroluminescence display device is included in an electro-optical device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

8. An electroluminescence display device having a display portion, comprising:
a substrate having an insulating surface; and
a plurality of thin film transistors in said display portion over said substrate, each thin film transistor having:
an active layer formed by patterning a semiconductor film which has a thickness of 100 to 700 Å;
a thermal oxide film of said semiconductor on said active layer; and
an insulating deposition film over said active layer with said thermal oxide film interposed therebetween,
wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film,
wherein crystal growth directions in said active layers differs from one of said plurality of thin film transistors to another, respectively, and
wherein said semiconductor film contains at least one element for promoting crystallization of said semiconductor throughout the semiconductor layer.

9. A device according to claim 8 wherein said semiconductor layer comprises silicon.

10. A device according to claim 8 wherein said element is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, and Au.

11. A device according to claim 8 wherein said element is contained in said semiconductor film at a concentration of 1×10 14 to 5×10 18 atoms/cm 3 .

12. A device according to claim 8 wherein said element is contained in said semiconductor film at a concentration of 1×10 16 to 5×10 17 atoms/cm 3 .

13. A device according to claim 8 wherein said electroluminescence display device is an active matrix type display device.

14. A material according to claim 8 wherein said thickness of said semiconductor film is 150 to 450 Å.

15. A device according to claim 8 wherein said electroluminescence display device is included in an electro-optical device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

16. An electroluminescence display comprising:
a substrate having an insulating surface; and
a plurality of thin film transistors over said substrate, each thin film transistor having:
an active layer having at least one channel region, source and drain regions, and low impurity regions,
a thermal oxide film of said active layer thereon,
an insulating deposition film formed on the thermal oxide film, and
at least one gate electrode on said insulating deposition film,
wherein said active layers of the thin film transistors are formed by patterning a semiconductor film over said substrate,
wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film,
wherein directions of anisotropy of crystal structures in active layers differs from one of said plurality of thin film transistors to another, respectively, and
wherein said thermal oxide film is thicker than said active layer.

17. A device according to claim 16 wherein said semiconductor film contains an element selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, and Au.

18. A device according to claim 16 wherein said electroluminescence display device is an active matrix type display device.

19. A device according to claim 16 wherein said electroluminescence display device is included in an electro-optical device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

20. A device according to claim 16 wherein said semiconductor device is an electroluminescent display device.

21. An electroluminescence display device having a display portion, comprising:
a substrate having an insulating surface; and
a plurality of thin film transistors in said display portion over said substrate, each thin film transistor having:
an active layer formed by patterning a semiconductor film over said substrate, said active layer having at least one channel region, source and drain region, and at least one low impurity region, and
at least one gate electrode adjacent to said channel region with a gate insulating film with interposed therebetween,
wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film,
wherein crystal growth directions in said active layers differs from one of said plurality of thin film transistors to another, respectively.
wherein said semiconductor film includes a material for promoting crystallization of silicon.

22. A device according to claim 21 wherein said material is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, and Au.

23. A device according to claim 21 wherein said electroluminescence display device is an active matrix type display device.

24. A device according to claim 21 wherein said electroluminescence display device is included in an electro-optical device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

25. An electroluminescence display device having a display portion, comprising:
a substrate having an insulating surface; and
a plurality of thin film transistors in said display portion over said substrate, each thin film transistor having an active layer formed by patterning a semiconductor film over said substrate and at least one gate electrode adjacent to said active layer with a gate insulating film with interposed therebetween;
a pixel electrode connected to said thin film transistors, respectively; and
auxiliary capacitors using said pixel electrodes,
wherein said semiconductor film comprises a plurality of radial crystal grains of silicon through the whole area of the semiconductor film,
wherein crystal growth directions in said active layers differs from one of said plurality of thin film transistors to another, respectively, and
wherein said substrate is selected from the group consisting of a glass substrate, a quartz substrate, and a semiconductor substrate.

26. A device according to claim 25 wherein said semiconductor film includes a material for promoting crystallization of silicon introduced into the whole area of said active layer and said material is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, and Au.

27. A device according to claim 25 wherein said electroluminescence display device is an active matrix type display device.

28. A device according to claim 25 wherein said electroluminescence display device is included in an electro-optical device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

29. A device according to claim 25 wherein said semiconductor is an electroluminescent display device.

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